Pen mechanisms



Ja nIZZ, 1957- J. E. FIELDEN 778,711

PEN MECHANISMS Filed April 13, 1953 2 Sheets-Sheet 1 lzzvelzznp I 66 Zdezv J. E. FIELDEN PEN MECHANISMS Jan. 22, 1957 2 Sheets-Shea; 2

Filed April @3, 1953 United States Patent F PEN MECHANISMS John E. Fielden, Wythenshawe, Manchester, England, as-

signor, by mesne assignments, to Robertshaw Fulton Controls Company, Greensburg, Pa.

Application April 13, 1953, Serial No. 348,228

Claims priority, application Great Britain April 21, 1952 6 Claims. (Cl. 346-439) This invention relates to pen mechanisms and more particularly to pen mechanisms used in recording instruments. The object of the invention is to provide an improved pen mechanism, in which the colour of the ink used for writing may be changed at will.

According to the invention indexing means are provided for rotating, through a preset angle, a writing head constituted by a plurality of pens, each time a shaft supporting the said head is translated from its position of writing to another position, said shaft having sliding connection with driving means for producing the writing movement of the pen.

In one embodment of the invention, the writing head comprising two or more pens each with its reservoir of ink is mounted rigidly at one end of a radius shaft which can be rotated about its own axis, and also caused to move arcuately so as to cause the pens to write on the chart paper of a recording instrument in the normal manner. The arcuate movement of the shaft is communicated to it by means of an arm driven by the recorder movement, with a slotted part embracing the shaft.

The radius shaft is supported at its centre of arcuate movement by a spindle which is movable in a direction normal to the plane of writing of the pens and movement of this spindle causes a translational movement of the radius shaft. On the shaft is fixed a ratchet wheel having a number of teeth, corresponding to the number of pens used in the writing head, and a pawl attached to the spindle supporting member engages with one of said teeth when a translational movement of the radius shaft occurs and rotates the ratchet Wheel.

The radius shaft is provided with an index wheel having a plurality of faces equal in number to the number of pens, one of said faces being in contact with a yielding surface when the radius shaft is in the position of Writing.

It will be evident that the system described above, is not limited solely to pen mechanisms in which the writing movement is arcuate but can also be applied in cases where the pen movement is linear.

Referring to the accompanying drawings:

Figure l is a perspective view of a device in accordance with the invention.

Figure 2 is a vertical section of the device shown in Figure 1.

Figure 3 is an elevation of the upper part of the device, shown in Figure 1.

Figure 4 is a plan view of the device shown in Figure l.

The device illustrated has a writing head 1 with four pens 2 each supplied with ink of a different color from an ink reservoir 3. The head 1 is fixed at the lower end of a radius shaft 4. The upper end of the shaft 4 is rotatable in a block 5 and carries a square index plate 6 in which are set four pins 7. A collar 8 is secured to the shaft 4 by a grub screw 9 to locate the shaft in the block 5,

' Patented Jan. 22, 1957 "ice The block 5 is carried by a spindle 10 which is sildable in a bush 11. The bush 11 carries at the end nearer to the block 5, an arm 12 having at its further end a slotted guide 13 embracing the shaft 4, a spring 14 which bears against the index plate 6, and a pawl 15 adapted to engage the pins 7 and pivotally mounted on a pin 16 in a slot formed in the end of the bush.

The bush 11 is mounted so as to be rotated but not axially displaced by a recording appliance and as it turns it swings the arm 12 and the guide 13 which displaces the shaft 4 carrying the pens. The pen which is for the time being in the position below the arm 12 in Figure 2 marks a trace on a paper chart in accordance with the movements imparted to the shaft 4.

The recorder may be provided with means (not shown) for longitudinally displacing the spindle 10 in the bush 11 at predetermined intervals, or other means may be provided for displacing the spindle. When the spindle is displaced, the block 5 together with the shaft 4 is moved to the left (Figures 2, and 4), and the pawl 15, engaging one of the pins 7, causes the plate 6 with the shaft 4 and pens 2 to rotate through with respect to the block 5. The shaft 4 moves in the slot in the guide 13 and the pen which is in the writing position is moved away from the chart, so that it is no longer in contact therewith as the head 1 turns to bring the next pen into the writing positions. Then the spindle 10 is retracted and the shaft 4 moves back to bring the next pen into contact with the chart. The pawl 15 slips over the next pin 7 and then engages it in readiness for the next operation, the spring 14 bearing against the next side of the plate 6 and ensuring its correct location, as well as holding it against reverse rotation as the pawl 15 slips over the pin 7.

What I claim is:

1. A marking device for a recording instrument comprising a rotatable hollow member, a spindle mounted for slidable movement in said rotatable member, bearing means carried by said spindle for movement laterally of said rotatable member, a shaft journaled at one end in said bearing means and extending normal to said spindle, a plurality of spaced marking means on the other end of said shaft, means for connecting said rotatable member to said shaft for imparting pivotal movement thereto upon rotation of said rotatable member, and means for connecting said shaft to said rotatable member for imparting axial rotation to said shaft upon said lateral movement of said bearing means.

2. A marking device for a recording instrument comprising a rotatable hollow member, a spindle mounted for slidable movement in said rotatable member, bearing means carried by said spindle for movement laterally of said rotatable member, a shaft journaled at one end on said bearing means and extending normal to said spindle, a plurality of spaced marking means on the other end of said shaft, an elongated arm carried by said rotatable member and extending substantially parallel with said shaft, and a guide element on said arm having an elongated slot through which said shaft extends for imparting pivotal movement thereto upon rotation of said rotatable member.

3. A marking device for a recording instrument com prising a rotatable hollow member, a spindle mounted for slidable movement in said rotatable member, bearing means carried by said spindle for movement laternally of said rotatable member, a shaft journaled at one end on said bearing means and extending normal to said spindle, a plurality of spaced marking means on the other end of said shaft, means for connecting said rotatable member to said shaft for imparting pivotal movement thereto upon rotation of said rotatable member, a ratchet member secured to said shaft adjacent said rotatable member and a pawl mounted on said rotatable member for operative engagement with said ratchet member for imparting axial rotation to said shaft upon said lateral movement of said bearing means.

4. A marking device as claimed in claim 3 wherein said'ratchet member includes a polygonal plate, and yieldable means operatively engageable with said plate for maintainingsaid marking means in selected position.

5. A marking device for a recording instrument comprising a rotatable hollow member, aspindle mounted for slidable movement in said rotatable member, bearing means carried by said spindle for movement laterally of aid rotatable member, a shaft journaled at one end on said bearing means and extending normal to said spindle, a plurality of spaced marking means on the other end of said shaft, an elongated arm carried by said rotatable member and extending substantially parallel with said shaft, a guide element on said arm having an elongated slot through which said shaft extends for imparting pivotal movement thereto upon rotation of said rotatable member, a ratchet member secured to said shaft adjacent said rotatable member, and a pawl mounted on said rotatable member for operative engagement with said ratchet member for imparting axial rotation to said shaft upon said lateral movement of said beairng means.

6. A marking device as claimed in claim 5 wherein said ratchet member includes a polygonal plate, and yieldable means operatively engageable with said plate for maintaining said marking means in selected position.

References Cited in the file of this patent UNITED STATES PATENTS 

